Understand the exam format

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Local Exams Format

Multiple Choice

110 min | 60 multiple-choice questions
Covers broad chemistry topics

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National Exams Format

Part I: Problem Solving

90 min | 60 multiple-choice questions
Covers broad chemistry topics


Part II: Problem Solving

105 min | 8 written questions
Covers chemical theories and models


Part III: Lab Practical

90 min | 2 laboratory practicals
Involves problem solving in the laboratory

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Multiple Choice Topics

Multiple choice USNCO (both local and national) exams cover the following topics:

Questions 
Topic
 1 – 6 Stoichiometry/Solutions
 7 – 12 Descriptive/Laboratory
 13 – 18 States of Matter
 19 – 24 Thermodynamics
 25 – 30 Kinetics
 31 – 36 Equilibrium
 37 – 42 Oxidation - Reduction
 43 – 48 Atomic Structure/Periodicity
 49 – 54 Bonding/Molecular Structure
 55 – 60 Organic/Biochemistry

Number of Nominees

More than 1,000 students sit for the three-part National Exam each April. Coordinators nominate students for the National Exam based on the results of the Local Competitions. Each Local Section can nominate only a certain number of students determined by the number of its ACS members. No more than two students from any given school can compete in the National Exam.

See the allowed numbers of nominees below or downoad a PDF of the allotment of nominees by ACS Local Section.

ACS MembersUSNCO Nominees
1–100010
1001-135011
1351-170012
1701-205013
2051-240014
2401-275015
2751-310016
3101-345017
3451-380018
3801-415019
ACS MembersUSNCO Nominees
4151-450020
4501-485021
4851-520022
5201-555023
5551-590024
5901-625025
6251-660026
6601-695027
6951-730028
7301-765029

Scoring

ACS calculates the average number of correctly answered questions by topic area. Based on this average, each student's score in a particular topic is compared to the overall average and rated as: Below Average, Average, Above Average, or Outstanding Performance.

Only student scores for Part I (multiple-choice) are sent to the Local Section coordinators to be distributed to students.

Results

The 20 top-scoring students are invited to attend a study camp to compete for a spot in the U.S. team. Based on the score of their overall performance, some students are recognized with High Honors and Honors and receive a certificate from the USNCO national office. Approximately the top 50 students are recognized as High Honors and the next 100 as Honors. The list of High Honor and Honor students is published on the USNCO website.

Learn about the exam format and how to prepare for exams.